Queen are at work on a possible new release, which would use unreleased Freddie Mercury vocals. In addition to Mercury’s highly anticipated duets with Michael Jackson, Brian May has revealed that the group have found even more unused material.

“There’s more in there than we thought, in the Queen source archive,” May recently told Mojo magazine. “I’m a little nervous of saying there’s an album there, but there’s certainly a few tracks ... We’ve found some Freddie vocals, some demos.”

The guitarist compared the project to Queen’s 1995 album Made In Heaven, released four years after Mercury’s death. As with those tracks, Queen are taking Mercury’s unused takes, cleaning them up, and adding original music. “If we find an analogue 24-track of Freddie singing something that never got finished, the first thing we do is ... make [a digital] copy at the highest resolution you can,” May said. “Then we start weaving our tapestry.”

Last month, drummer Roger Taylor gave an update on the three Mercury/Jackson duets that were rediscovered this summer. “They’ve been hanging around for years and years and Michael’s estate haven’t really been able to make their mind up about what to do with them,” he told Classic Rock magazine. “We suggested we finish them and see. They’re pretty good – one of them is great.”

In an earlier interview with the Times, May mentioned that he hoped to release these songs before the end of 2013. He has apparently been working with producer William Orbit to finish the tracks, which were originally recorded in 1983.